This one was done with about 13,500 college women. The study was to find out what percentage of women had an orgasm when having vaginal sex.
About 32% had an orgasm the first time with that man, if they did not plan to continue the relationship. If she did want to stay together, it was higher.
About 51% had an orgasm with a man after having sex with him over 6 times previously. What was most interesting was, what could increase the chances of having an orgasm. Meaning above that 32%.
It was an 18% greater chance of an orgasm if she manually touched herself first.
32 + 18 = 50% chance of an orgasm.
It was an 9% greater chance of an orgasm if he performed oral sex on her first.
32 + 9 = 41% chance of an orgasm.
It was an 15% greater chance of an orgasm if they had anal sex first.
32 + 15 = 47% chance of an orgasm.
(This study seems to prove something that Pierre has known for many years.)

PW

This study was done by Harvard University and involved 21 universities or colleges.
I would like to add my personal observation. In my years of observing and listening to a few hundred friends tell about their experiences, only 2 girls that I knew had sex with a guy for the first time, when alcohol was NOT involved. We were all on a trip, and the four of them took turns in a hotel room for an "afternoon delight". The guys were very good looking, (as were the girls).
In every other case, drugs and/or alcohol were involved. Obviously their inhibitions were left at the door of the bar, night club, rock concert or frat house.
Now think about Pierre's track record with women that he interviews, without involving alcohol. Very impressive.